Ok heres what you have to do:
1) Take off the servo horn (the big round white thing should be on there by default)
2) Unscrew all 4 screws from the back of your servo
3) Remove the top of the servos case (the part on the side where you can see the small geared shaft sticking up) *Make sure not to let any of the gears fly out at you
4) Remove the main gear(the biggest one opposite of the one that also has that small geared shaft which will actually require you to remove 2 other things first. Youll see when you get in there) *Make sure that when you take them out, you put them on a very clean surface so that they gear grease doesnt get dirty or washed off.
5) Plug your servo into your robots mother board like you normally would
6) Load up your project in AVR Studio
7) Click on the "Connect to the selected AVR Programmer" button. It looks like a little black IC with the white letters "AVR" on it. It should be 2 bars below the Help menu button and to the right...
When the window pops up, go down to where it says "Input HEX File" under "Flash" and click the little button labeled "..."
9) Select the HEX file that you should have downloaded for zeroing or centering the servo and click "OK"
10) Click "Program"
*Your gears should now start rotating in the servo
11) You should see a little raised structure in the servo coming out of from where you took the main gear off, this is the Potentiometer(pot) head. Slowly start to turn this in either direction until you see the gears stop moving. It should not take much force at all to turn the servo so be careful not to break it.
12) When you see that your servos gears stop completely, apply super glue carefully to the pot head. Make sure you dont turn the pot head at ALL or you could throw off the calibration (I did this a few times lol)
13) Also, make sure that you dont get super glue anywhere but on the potentiometer and the plastic just around the potentiometer to keep it from moving at all.
14) Now you will probably have to modify the the main gear. You should see a small "block" protruding from the shaft of this main gear, cut that off.
15) On the underside, you should see a notch that sat on top of the pot head. If you got lucky, you should just be able to remove some sort of catch system like this
If not, you need to dremel it out BUT BE CAREFUL NOT TO MESS UP THE GEARS ON THE OUTSIDE!
I regret not having taken pictures of when I did it.
Just make sure that there is enough room for the gear to spin without interfering(touching at all) with the pot.
16) Wait for the glue to dry (wait like a half hour to an hour just to be safe) and then put the main gear back in and gently try to spin it a little bit to make sure its not catching on the dried glue or anything
17) Put it back together and put the screws in
Post if there are any problems with any step